Oh yes, one thing more. Using an index for a field with only four possible
values will give you lots of duplicates which makes maintaining the index
more difficult for IB. Change your index definition to
create index test_idx on test(code, TestID);

Set

At 08:39 01.02.2001 +0100, you wrote:

>I guess it could be garbage collection. Try running "select count(*) from
>test" (and remember to commit) after deleting. If garbage collection is the
>issue this will take some time, but your performance afterwards should
>improve.
>
>Set
>
>At 04:30 01.02.2001 -0000, you wrote:
>>Hi!
>>
>>In a database with containing only one table (details see below) I
>>insert first around 20000 records and afterwards I delete half of
>>them. After deleting this records I have performance problems
>>accessing the table. It is best shown when I do a GBAK:
>>
>>GBAK-Time after inserting before deleting: 6min
>>GBAK-Time after deleting: 25min
>>
>>During GBAK of the deleted version I see Interbase using a lot of CPU
>>time but not accessing hard disk very often. This is different to the
>>non deleted version which is doing mainly I/O stuff. The additional
>>time for the deleted version is used when GBAK writes the table with
>>the deleted records.
>>
>>I'm using IB 6.01 on W2k (Standard installation without any change on
>>probably performance sensitive parameters).
>>
>>My database has the following structure:
>>
>>create table Test (
>> TestID Numeric(18,0) not null,
>> Code SmallInt,
>> Text VarChar(120),
>> constraint Test_PK Primary Key (TestID));
>>
>>create index test_idx on test(code);
>>
>>create generator IDGen;
>>
>>There are no other tables in the database. The database is filled with
>>random data for field Text (length between 10 and 40 characters) and
>>random data for field code with values between 0..3.
>>
>>My delete is: DELETE FROM Test WHERE Code in (1,3)
>>
>>Has anybody an idea about this behavior?
>>
>>Thank's for any help and hints!
>>
>>Daniel Achermann
>>
>>
>>
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>>
>>
>>
>>
>
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